DEVICE FOR BIOCHEMICAL MEASUREMENTS OF VESSELS AND FOR VOLUMETRIC ANALYSIS OF LIMBS

Abstract

A non-wounding system for bio-morphological characterization of a human limb including a device for geometric and volumetric, data, including: a plurality of systems for three-dimensional images acquisition for imaging the limb, an articulated and motorized frame arranged for positioning some of the systems for acquisition in a peripheral manner with respect to the limb, a device for processing the data, arranged for representing the data in the form of a points presenting a set of three-dimensional coordinates, a device for biomechanical measurements including a probe holder fixing at least one ultrasound probe for imaging the vascular system relative to the limb and a force sensor measuring the pressure exerted by said probe on the limb, and a device for analysis, for merging the volumetric data and some of the anatomical and biomechanical data, and also for determining morphological variables and/or biomechanical variables of the vascular system of the limb.

Claims

1. A non-wounding system for bio-morphological characterization of a human limb comprising a device for geometric and volumetric measurements, comprising: a plurality of systems for three-dimensional images acquisition arranged for imaging said limb; an articulated and motorized frame arranged both for positioning at least some of the plurality of the systems for acquisition in a peripheral manner with respect to said limb, and also for moving at least some of the plurality of the systems for acquisition with respect to said limb; a device for processing the geometric and volumetric data, arranged for representing the acquisition data in the form of a plurality of points presenting a set of coordinates in a three-dimensional frame of reference; a device for anatomical and biomechanical measurements comprising a probe holder comprising: an ultrasound probe for imaging the vascular system relating to said limb; a force sensor arranged for measuring the pressure exerted by said probe on the limb, said force sensor being fixed to said ultrasound probe; and a device for analysis, arranged both for merging at least some of the volumetric data and at least some of the anatomical and biomechanical data, and also for determining morphological variables of the limb and/or biomechanical variables of the vascular system of said limb.

2. The system according to claim 1, characterized in that at least some of the plurality of systems for three-dimensional images acquisition of the system according to the invention operate synchronously.

3. The system according to claim 1, characterized in that the device for geometric and volumetric measurements also comprises a tool assisting the geometrical and volumetric measurement of said limb, arranged for determining representative areas of the limb for the determination of its shape and its volume.

4. The system according to claim 1, characterized in that the probe holder is mounted on an articulated and/or motorized arm fixed to the frame, and arranged for bringing said probe holder into contact with the limb and/or for moving said probe holder on said limb.

5. The system according to claim 1, characterized in that the device for anatomical and biomechanical measurements comprises at least one sensor for measuring the interface pressure, said at least one sensor being placed in contact with the skin of said limb.

6. A method for assisting the definition, selection or adaptation of a compression orthosis for a limb, implementing the system for bio-morphological characterization according to claim 1, comprising at least one of the following steps: geometric and volumetric measurements of said limb; biomechanical measurements of said limb; merging of the geometric and/or volumetric and biomechanical measurements in order to correlate at least some of said geometric and/or volumetric measurements and at least some of said biomechanical measurements; and determining at least one biometric variable and/or at least one volumetric parameter.

7. The method according to claim 6, characterized in that the step of biomechanical measurements of the limb is carried out at least during the step of geometric and/or volumetric measurements.

8. The method according to claim 6, characterized in that it also comprises a step of defining, selecting or adapting a compression orthosis for the limb, as a function of the at least one biometric variable and/or the at least one geometric and/or volumetric variable.

9. The method according to claim 6, characterized in that it comprises an additional step of developing a biomechanical model predicting the effects of the compression orthosis on the limb and its vascular system.

Description

DESCRIPTION OF THE FIGURES AND EMBODIMENTS

[0107] Other advantages and characteristics of the invention will become apparent through the following description of several embodiments given by way of indicative and non-limitative examples, and from the attached diagrammatic drawings, in which:

[0108] FIG. 1A shows an overall diagrammatic view of the device for volumetric measurement according to the invention,

[0109] FIG. 1B shows a first embodiment of the device for volumetric measurement according to the invention,

[0110] FIG. 2 shows the probe holder used for carrying out some of the biomechanical measurements of the vascular system of the limb,

[0111] FIG. 3 shows an articulated arm for the probe holder, according to a particular embodiment of the invention,

[0112] FIG. 4 shows the principle of bio-morphological characterization according to the invention, and

[0113] FIG. 5 shows an analysis sequence of ultrasound images produced during the biomechanical measurements.

[0114] The embodiments which will be described hereinafter are in no way limitative; it is possible, in particular, to imagine variants of the invention comprising only a selection of characteristics described hereinafter, in isolation from the other characteristics described, if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention with respect to the state of the prior art. This selection comprises at least one, preferably functional, characteristic without structural details, or with only a part of the structural details if this part alone is sufficient to confer a technical advantage or to differentiate the invention with respect to the state of the art.

[0115] In particular, all the variants and all the embodiments described can be combined together if there is no objection to this combination from a technical point of view.

[0116] In the figures, the components common to several figures retain the same reference number.

[0117] An orthosis is an appliance which compensates for an absent or deficient function of a limb, assists a joint or muscle structure, stabilizes a body segment during a phase of rehabilitation or rest. It differs from a prosthesis, the function of which is to replace a missing part of the human body.

[0118] FIG. 1A shows an overall diagrammatic view of the device for volumetric measurement 100 according to the invention, and FIG. 1B shows a particular embodiment of the invention.

[0119] The patient, one of whose limbs is to benefit from the application of an orthosis, is positioned on a measurement bench, a part of which is shown in FIG. 1B. The measurement bench typically comprises a first structureoptional and not shownallowing the patient to be comfortably positioned for the morphological analysis of the limb on which the orthosis is to be put in place, as well as a second structure 100 shown in FIGS. 1A and 1B, making it possible to place said limb 110 inside a measurement area.

[0120] More particularly, FIG. 1A diagrammatically shows such an setup for characterizing a lower limb 110.

[0121] The lower limb 110 is placed inside an articulated frame 120 which has several three-dimensional sensors 131-137 in the space peripheral to said limb 110. The frame 120 is constituted by a base 124 at the end 123 of which two sensors 137a, 137b make it possible to image the arch of the foot of the limb 110. As an extension with respect to the base 124, a support 125 extends in a direction substantially parallel to the elongation of the lower limb 110.

[0122] According to a particular embodiment of the invention, the support 125 supports a circular arm 121, to which the three-dimensional sensors 131-135 are fixed.

[0123] The circular arm 121 is articulated in order to allow release to the right or to the left and thus allow the patient to introduce their limb 110 into, or remove it from, the measurement area inside said frame 120.

[0124] According to a particular embodiment of the invention, compatible with any version of the frame 120, the support 125 can be telescopic, in order to adapt to the sizes of the lower limbs of different patients.

[0125] In FIG. 1A, the circular arm 121 supports five three-dimensional sensors 131-135 which can be articulated and/or motorized so as to carry out a scan around the lower limb 110.

[0126] Optionally, the circular arms 121, 122 can also, or alternatively, be articulated and/or motorized so as to carry out a rotation around the lower limb 110.

[0127] In other words, the articulation of the different sensors can be collective, i.e. implemented by the articulation and/or the rotation of the arm or arms supporting them and/or of the support; alternatively, the articulation of the different sensors can be individual, each sensor having its own means for articulation and/or rotation with respect to the support or the frame supporting it.

[0128] The means for articulation and/or rotation are well known per se, and not described here.

[0129] The distance separating the circular arm 121 from the base 124 can also be adjustable so as to adapt the volumetric measurement device 100 to the dimensions of the limb 110 to be characterized.

[0130] In addition to the volumetric measurement device 100, FIG. 1A also shows the putting in place of surface pressure sensors 141-143 used for measuring, for example, the pressure exerted by the orthosis on the lower limb 110 when the orthosis is put in place, or the surface pressure in the absence of the orthosis. In FIG. 1A, three sensors 141-143 are thus arranged along the lower limb 110.

[0131] Preferentially, the position of the surface pressure sensors 141-143 can be chosen so as to characterize the areas which are also imaged by the three-dimensional sensors 131-137 in order to be ableultimatelyto merge the data and establish a more complete analysis of said limb 110 and of the effect of the orthosis.

[0132] In the particular embodiment shown in FIG. 1B, the lower limb 110 is placed inside an articulated frame 120 which has several three-dimensional sensors 131-137 in the space peripheral to said limb 110. The frame 120 is constituted by a base 124 at the end 123 of which a first sensor 137 makes it possible to image the arch of the foot of the limb 110. As an extension with respect to said base 124, a support 125 extends in a direction substantially parallel to the elongation of the lower limb 110 and supports two circular arms 121, 122, to which the three-dimensional sensors 131-136 are fixed.

[0133] In this example, each circular arm 121, 122 is arranged, both for allowing easy insertion of the limb 110 to be characterized inside the device 100 and also is articulated so as to move the three-dimensional sensors 131-136 around said limb.

[0134] As explained previously, the movement of the three-dimensional sensors 131-136 around said limb can be collective, using motorization and an independent articulation of each arm and/or by an independent articulation and motorization of each sensor in order to allow the lattercollectively and/or individuallyto image several areas of the limb.

[0135] FIG. 2 shows the probe holder 200 used for carrying out some of the biomechanical measurements of the vascular system of the limb 110.

[0136] The probe holder is constituted by a housing 201 inside which, or onto which, an ultrasound probe 210 is fixed, mounted on a linear translation support and connected to a force sensor 220. The probe holder 200 is designed so as to allow the insertion of several types of ultrasound probes 210. It thus comprises means for fixing said probe, not shown in FIG. 2, such as for example at least one ring passing through the housing 201 and around the probe 210. The active end of the ultrasound probe 210 projects beyond the probe holder in order to be able to be brought into contact with the skin of the limb 110 to be characterized.

[0137] The force sensor 220 is fixed clos to the ultrasound probe 230 by any fixing means 230, and in such a way that it is in contact with the skin of the limb 110 when the ultrasound probe 210 is.

[0138] The most significant force measurements are those carried out in the axis of the ultrasound probe 210, i.e. substantially parallel to the active surface 211 of said probe 210. However, additional measurements of forces in the transverse directions can make it possible to fine-tune the measurements and correct certain possible errors linked to a defect of alignment of the force sensor 220 with respect to said ultrasound probe 210.

[0139] The force sensor 220 is arranged for measuring at least the force normal to its contact surface 221.

[0140] FIG. 3 shows an articulated arm 300 for the probe holder 200 according to a particular embodiment of the invention.

[0141] The probe holder 200 is fixed onto an articulated arm 300 using fixing means 307. The articulated arm 300 can be independent of the volumetric measurements device 100, or fixed to said volumetric measurements device 100.

[0142] At the end of the articulated arm 300, a ball joint 306 allows the probe holder 200 to carry out three rotations.

[0143] At the base 301 of the articulated arm 300, a ball joint 302 makes it possible to orientate the latter in any direction.

[0144] Between the two ends, the articulated arm 300 can comprise an unlimited number of kinematic links. In the example shown in FIG. 3, the articulated arm is composed of two intermediate segments 303, 305, linked to each other by a ball joint 304.

[0145] FIG. 4 shows the principle of bio-morphological characterization according to the invention, and comprises the following steps: [0146] the patient is positioned on the analysis bench, and their limb 110 is placed inside the frame 120 supporting the sensors 131-137. Optionally, the limb 110 on which the measurements are to be carried out can be held by a temporary retention device; [0147] in step 401, the volumetric measurements are carried out. The frame 120 moves the three-dimensional sensors 131-137 in order to scan at least a part of said limb 110; [0148] in step 402, at least one ultrasound measurement of at least a part of the vascular system of said limb is carried out using the probe holder 200, and more particularly via the ultrasound probe 210, in order to determine certain morphological variables of said vascular system, in particular the diameter of the vessel in step 404; [0149] in step 405, the development in the force exerted by the probe 210 on the limb 110 during the ultrasound measurements 402 is recorded via the force sensor 220 arranged on the probe holder 200. [0150] in step 403, measurements of the surface pressure exerted by the orthosis on the limb 110 are carried out using the interface pressure sensors 141-143; [0151] merging of the different data and correlation in step 407, analysis of the measurements carried out in order, in particular, to determine the effectiveness and the impact of the compression orthosis on the vascular system of said limb 110 and, finally, selecting or adapting an orthosis in a specific manner; [0152] optionally, assisting the prescription of particular compression orthoses in step 408, resulting from the previous measurements and analyses.

[0153] FIG. 5 shows an analysis sequence of ultrasound images produced during the step of biomechanical measurements,

[0154] According to this particular analysis method, a region of interest (ROI) is first determined 501. It comprises, in particular, the vascular vessel 511, the morphological characteristics of which are sought.

[0155] Then the region of interest is binarized in step 502 as a function of a threshold defined as a function of the parameters of measurements and/or of the user; it can for example be carried out according to a method called gradient calculation, making it possible to carry out adaptive thresholding. It can also be predefined in a manner that is invariant with respect to the images and/or the patients.

[0156] The following step 503 consists of reconstructing a coherent geometry of the cell thus isolated in the region of interest, via an operation of mathematical morphology.

[0157] It is then possible to determine the position of the walls of the vessel in step 504 and in step 505. According to the orientation of these walls and with respect to the vicinity of the central part of the region of interest, the average diameter of the vessel is calculated. The position and evolution of the cross-section along the blood vessel is measured.

[0158] Advantageously, the position, the orientation and the dimensions of the walls of the vessel are measuredoptionally using a simplified ellipsoidal model of the cross-section of said vessel, in order to calculate the transverse surface (and evolution thereof) of said vessel at least one position.

[0159] At least some of the diameters and/or positions and/or dimensions and/or orientations calculated are recorded in a file.

[0160] A simplified visualization 506in the form of an ellipsoidal representation of the vesselsmakes it possible to observe in real time the variation in the diameter of said vessels, said variation being calculated according to a longitudinal and/or transverse section.

[0161] Of course, the invention is not limited to the examples which have just been described and numerous adjustments can be made to these examples without exceeding the scope of the invention. In particular, the different characteristics, forms, variants and embodiments of the invention can be combined together in various combinations to the extent that they are not incompatible or mutually exclusive. In particular, all the variants and embodiments described previously can be combined.